Long-Term Outcomes of Long-Course Chemoradiotherapy vs. Short-Course Radiotherapy Followed by Consolidation Chemotherapy in Rectal Cancer

Abstract

Purpose: Previous studies have demonstrated that short-course radiotherapy (SCRT), followed by consolidation chemotherapy (CCT), produces oncologic outcomes comparable to those of long-course chemoradiotherapy (LCRT). However, more recent long-term data have raised concerns regarding the durability of these benefits. This study aimed to assess the long-term surgical and oncologic outcomes of SCRT with CCT vs. LCRT, using data from the ESCORT trial. Materials and Methods: This comparative study included 62 patients with locally advanced rectal cancer. Patients in the SCRT group (n=27) were prospectively enrolled in the ESCORT trial (NCT03676517), a single-arm phase II study conducted from 2018 to 2020. They received five daily fractions of 5 Gy, followed by two cycles of XELOX, and surgery after 4 weeks. A matched cohort of 35 patients who underwent LCRT during the same period was retrospectively identified from institutional records. Results: With a median follow-up of 4.75 years for the SCRT group and 4.94 years for the LCRT group, the 5-year overall survival rates were similar between the groups (SCRT: 100% vs. LCRT: 97.1%, p=0.382). The 5-year disease-free survival (DFS) rates were 83.6% for SCRT and 70.3% for LCRT (p=0.237). In multivariable analysis, SCRT was not associated with inferior DFS (hazard ratio, 0.53; 95% confidence interval, 0.14-2.04). Delayed anastomosis-related complications occurred at similar rates (18.5% vs. 20.0%; p=0.884). Conclusion: SCRT with CCT demonstrated long-term oncologic outcomes and surgical safety comparable to those of LCRT, supporting its role as a viable alternative, particularly in resource-constrained healthcare settings.